Remote access to local network

ABSTRACT

Multiple protocol tunnels (e.g., IPsec tunnels) are deployed to enable an access terminal that is connected to a network to access a local network associated with a femto access point. A first protocol tunnel is established between a security gateway and the femto access point. A second protocol tunnel is then established in either of two ways. In some implementations the second protocol tunnel is established between the access terminal and the security gateway. In other implementations the second protocol tunnel is established between the access terminal and the femto access point, whereby a portion of the tunnel is routed through the first tunnel.

CLAIM OF PRIORITY

This application is a divisional of U.S. patent application Ser. No.12/619,162, entitled “REMOTE ACCESS TO LOCAL NETWORK,” which claims thebenefit of and priority to commonly owned U.S. Provisional PatentApplication No. 61/115,520, filed Nov. 17, 2008; U.S. Provisional PatentApplication No. 61/145,424, filed Jan. 16, 2009; U.S. Provisional PatentApplication No. 61/150,624, filed Feb. 6, 2009; and U.S. ProvisionalPatent Application No. 61/164,292, filed Mar. 27, 2009, the disclosureof each of which is hereby incorporated by reference herein.

CROSS-REFERENCE TO RELATED APPLICATION

The U.S. patent application Ser. No. 12/619,162 is also related to aconcurrently filed and commonly owned U.S. patent application Ser. No.12/619,174, entitled “REMOTE ACCESS TO LOCAL NETWORK VIA SECURITYGATEWAY,” the disclosure of which is hereby incorporated by referenceherein.

BACKGROUND

1. Field

This application relates generally to wireless communication and morespecifically, but not exclusively, to improving communicationperformance.

2. Introduction

Wireless communication systems are widely deployed to provide varioustypes of communication (e.g., voice, data, multimedia services, etc.) tomultiple users. As the demand for high-rate and multimedia data servicesrapidly grows, there lies a challenge to implement efficient and robustcommunication systems with enhanced performance.

To supplement conventional mobile phone network access points,small-coverage access points may be deployed (e.g., installed in auser's home) to provide more robust indoor wireless coverage to mobileaccess terminals. Such small-coverage access points may be referred toas femto access points, access point base stations, Home eNodeBs(“HeNBs”), Home NodeBs, or home femtos. Typically, such small-coverageaccess points are connected to the Internet and the mobile operator'snetwork via a DSL router or a cable modem.

In some cases, one or more local services may be deployed at the samelocation as a small-coverage access point. For example, a user may havea home network that supports a local computer, a local printer, aserver, and other components. In such cases, it may be desirable toprovide access to these local services via the small-coverage accesspoint. For example, a user may wish to use his or her cell phone toaccess a local printer when the user is at home.

In general, a node on the public Internet may not be able to initiatecommunication with a device on a home network because this device isprotected by a firewall and the network address translator (NAT) withinthe home router. Accordingly, a need exists for efficient and effectivemethods for remotely accessing a local network.

SUMMARY

A summary of sample aspects of the disclosure follows. In the discussionherein, any reference to the term aspects may refer to one or moreaspects of the disclosure.

The disclosure relates in some aspects to using multiple protocoltunnels (e.g., IPsec tunnels) to enable an access terminal that isconnected to a network (e.g., an operator's network, the Internet, etc.)to access a local network associated with a femto access point. A firstprotocol tunnel is established between a security gateway and the femtoaccess point. A second protocol tunnel is then established in either oftwo ways. In some implementations the second protocol tunnel isestablished between the access terminal and the security gateway. Inother implementations the second protocol tunnel is established betweenthe access terminal and the femto access point, whereby a portion of thetunnel is routed through the first tunnel.

Through the use of these schemes, an access terminal may reach a localInternet Protocol (IP) network or server that is in the same domain as afemto access point even when the access terminal is not connectedover-the-air with the femto access point. Thus, a remotely locatedaccess terminal may be provided with the same local IP capability aswhen the access terminal is connected to the femto access pointover-the-air.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other sample aspects of the disclosure will be described inthe detailed description and the appended claims that follow, and in theaccompanying drawings, wherein:

FIG. 1 is a simplified block diagram of several sample aspects of acommunication system where an access terminal remotely accesses a localnetwork via protocol tunnels terminating at a security gateway;

FIG. 2 is a flowchart of several sample aspects of operations that maybe performed to provide remote access to a local network via protocoltunnels terminating at a security gateway;

FIG. 3 is a flowchart of several sample aspects of operations that maybe performed to discover a security gateway;

FIG. 4 is a simplified block diagram of several sample aspects of acommunication system where an access terminal remotely accesses a localnetwork via layered protocol tunnels;

FIG. 5 is a flowchart of several sample aspects of operations that maybe performed to provide remote access to a local network via layeredprotocol tunnels;

FIG. 6 is a simplified block diagram of several sample aspects ofcomponents that may be employed in communication nodes;

FIG. 7 is a simplified diagram of a wireless communication system;

FIG. 8 is a simplified diagram of a wireless communication systemincluding femto access points;

FIG. 9 is a simplified diagram illustrating coverage areas for wirelesscommunication;

FIG. 10 is a simplified block diagram of several sample aspects ofcommunication components; and

FIGS. 11-16 are simplified block diagrams of several sample aspects ofapparatuses configured to facilitate remote access to a local network astaught herein.

In accordance with common practice the various features illustrated inthe drawings may not be drawn to scale. Accordingly, the dimensions ofthe various features may be arbitrarily expanded or reduced for clarity.In addition, some of the drawings may be simplified for clarity. Thus,the drawings may not depict all of the components of a given apparatus(e.g., device) or method. Finally, like reference numerals may be usedto denote like features throughout the specification and figures.

DETAILED DESCRIPTION

Various aspects of the disclosure are described below. It should beapparent that the teachings herein may be embodied in a wide variety offorms and that any specific structure, function, or both being disclosedherein is merely representative. Based on the teachings herein oneskilled in the art should appreciate that an aspect disclosed herein maybe implemented independently of any other aspects and that two or moreof these aspects may be combined in various ways. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, such an apparatusmay be implemented or such a method may be practiced using otherstructure, functionality, or structure and functionality in addition toor other than one or more of the aspects set forth herein. Furthermore,an aspect may comprise at least one element of a claim.

FIG. 1 illustrates several nodes of a sample communication system 100(e.g., a portion of a communication network). For illustration purposes,various aspects of the disclosure will be described in the context ofone or more access terminals, access points, and network nodes thatcommunicate with one another. It should be appreciated, however, thatthe teachings herein may be applicable to other types of apparatuses orother similar apparatuses that are referenced using other terminology.For example, in various implementations access points may be referred toor implemented as base stations or eNodeBs, access terminals may bereferred to or implemented as user equipment or mobiles, and so on.

Access points in the system 100 provide one or more services (e.g.,network connectivity) for one or more wireless terminals (e.g., accessterminal 102) that may be installed within or that may roam throughout acoverage area of the system 100. For example, at various points in timethe access terminal 102 may connect to an access point 106 (e.g., afemto access point associated with a local network) or other accesspoints (e.g., macro access points, not shown in FIG. 1). Each of theaccess points may communicate with one or more network nodes tofacilitate wide area network connectivity.

These network nodes may take various forms such as, for example, one ormore radio and/or core network entities. Thus, in variousimplementations a network node may provide functionality such as atleast one of: network management (e.g., via an operation,administration, management, and provisioning entity), call control,session management, mobility management, gateway functions, interworkingfunctions, or some other suitable network functionality. In the exampleof FIG. 1, sample network nodes are represented by, a public switcheddata network (PSDN) 108, an operator core network cloud 110, a securitygateway 112 (e.g., a femto security gateway), and an authenticationserver 114 (e.g., an authentication, authorization, and accounting (AAA)entity; a visiting location register (VLR), or a home location register(HLR)).

The nodes in the system 100 may employ various means to communicate withone another. Depending on its location, the access terminal 102 maycommunicate with an IP network 110 (e.g., to an access point of the IPnetwork 110, not shown) or the access point 106. In the example of FIG.1, the access terminal 102 is connected to an IP network 110 asrepresented by a communication link 118 (e.g., via a wireless or wiredconnection). The access point 106 may connect to a router 120 asrepresented by a communication link 122, the router 120 may connect tothe Internet 124 as represented by a communication link 126, thesecurity gateway 112 may connect to the Internet 124 as represented by acommunication link 128, and the security gateway 112 may connect to theIP network 110 as represented by a communication link 130.

Through the use of these communication links, the access terminal 102may communicate with various nodes in the system 100. When the accessterminal 102 is connected to the IP network, the access terminal 102may, for example, access services via an operator core network (e.g.,the core network of a cellular network) or some other network. Thus, theaccess terminal 102 may communicate with other access terminals andother networks.

When the access terminal 102 is connected to the access point 106, theaccess terminal may access nodes on a local network on which the accesspoint 106 resides along with one or more local nodes (represented bylocal node 134). The local node 134 may represent a device that resideson the same IP subnetwork as the access point 106 (e.g., a local areanetwork served by the router 120). In this case, accessing the localnetwork may involve accessing a local printer, a local server, a localcomputer, another access terminal, an appliance (e.g., a securitycamera, an air conditioner, etc.), or some other entity on the IPsubnetwork. When connected to the access point 106, the access terminal102 may access the local network without going through the operator corenetwork 110. In this way, the access terminal 102 may efficiently accesscertain services when the access terminal is, for example, at a homenetwork or some other local network.

When the access terminal 102 is connected to some other access point(e.g., the access terminal 102 is operating remotely in anothernetwork), the access terminal 102 may not be able to readily access thelocal network due to a firewall at the router 120. In the discussionthat follows two architectures are described for enabling an accessterminal to remotely access a local network.

FIGS. 1 and 2 describe an architecture that employs two protocoltunnels, both of which terminate at the security gateway 112. The firstprotocol tunnel is established between the security gateway 112 and theaccess point 106. The second protocol tunnel is established between thesecurity gateway 112 and the access terminal 102.

FIGS. 4 and 5 describe an architecture that employs two protocoltunnels, both of which terminate at the access point 106. The firstprotocol tunnel is established between the security gateway 112 and theaccess point 106. The second protocol tunnel is established between theaccess point 106 and the access terminal 102, whereby a portion of thesecond protocol tunnel is established within the first protocol tunnel.

In some aspects, these architectures may make use of an IP port openedby the protocol tunnel established between the security gateway 112 andthe access point 106 to enable remote access. In the architecture ofFIG. 1, the security gateway 112 inspects the packets received via thetunnel from the access terminal 102 and forwards these packets to thetunnel to the access point 106. In the architecture of FIG. 4, thesecurity gateway simply routes tunneled inbound packets from the accessterminal 102 to tunnel to the access point 106, and vice versa.

Advantageously, these architectures may have good synergy withconventional femto access point implementations. For example, a femtoaccess point that supports local IP access may already support assigninglocal IP addresses for access terminals and performing proxy addressresolution protocol (ARP) functions. In addition, a femto access pointmay already have a persistent IPsec tunnel with its femto securitygateway that traverses through any network address translation (NAT)between the femto access point and the femto security gateway. Also,there may be no need to provision additional authentication information(e.g., authentication information) for remote access terminal access(e.g., for authentication, authorization, and secure IPsec tunnel). Theauthentication information for remote access may be derived using one ofthe existing authentication information that the access terminal shareswith the local (e.g., home) network or the operator's network.

The following implementation details may be used in conjunction with thedescribed architectures. An operator may offer remote IP access as anadd-on service on a subscription basis. Capabilities such as DHCP/ARPare available at the femto access point to support remote IP access.Femto access points that can be reached by a given access terminal maybe configured as part of the access terminal (subscription) profile at ahome authentication server. Femto access points may be identified by afemto identifier or by realm (e.g., useful for groups of femto accesspoints in enterprise deployments). A user may invoke the service ondemand at the access terminal (e.g., by clicking “My Home”).

Referring again to FIG. 1, sample aspects of this architecture will nowbe described in more detail. The security gateway 112 acts as a virtualprivate network (VPN) gateway for a protocol tunnel established with theaccess terminal 102. In FIG. 1, traffic flow between the access terminal102 and the security gateway 112 (e.g., via links 118, and 130) isrepresented by dotted line 136 routed via a protocol tunnel (e.g., anIPsec tunnel) as represented by a pair of lines 138. Here, the innersource and destination addresses of a packet sent by the access terminalwill have local network addresses (e.g., as assigned by the router 120),while the outer source and destination addresses will be, for example,the macro IP address of the access terminal 102 and the IP address ofthe security gateway 112, respectively.

The security gateway 112 forwards any packets received from the accessterminal 102 to the access point 106 via a protocol tunnel establishedwith the access point 106. In FIG. 1, traffic flow between the securitygateway 112 and the femto access point 106 (e.g., via links 128, 126,and 120) is represented by dotted line 140 within a protocol tunnel(e.g., an IPsec tunnel) as represented by a pair of lines 142. In thistunnel, the inner source and destination addresses of packet sent by theaccess terminal will again be the local network addresses discussed inthe previous paragraph, while the outer source and destination addresseswill be, for example, defined by the tunnel 142.

Access terminal authentication is performed with the authenticationserver 114 (e.g., a home AAA) using a suitable algorithm. For example,some implementations may employ IKEv2 EAP-AKA or IKEv2 PSK (e.g.,reusing the existing IP subscription authentication information for theaccess terminal, e.g., as configured by an operator). The femto accesspoint may provide DHCP server functionality which the security gateway112 may request local IP to assign to the access terminal as part ofIKEv2.

The security gateway 112 forwards selected packets from the access point106 to the access terminal 102 (e.g., based on a forwarding policy or atarget address). The security gateway 112 is reachable via the macro IPaddress of the access terminal 102. Through the use of the above scheme,the access terminal 102 may use any available IP connectivity for remoteIP access.

In some implementations (e.g., when the access terminal 102 is on aremote network that is different than the operator network for theaccess point 102), an address conflict may arise when routing packetsfrom the access point 106 to the access terminal 102. To address thisissue, separate child security associations (CSAs) may be defined forthe tunnel 142. For example, a first CSA may be used to route trafficfrom the access point 106 that is destined for the access terminal 102(e.g., remote IP access traffic). A second CSA may then be used to routetraffic from the access point 106 that is destined for the operator corenetwork 110. The security gateway 112 may determine where to route apacket received from the access point 106 based on which CSA the packetwas received on. CSAs may be advantageously employed here since anotherunique protocol tunnel need not be defined and the authenticationinformation of the tunnel 142 may be reused.

Sample operations of the system 100 will now be described in more detailin conjunction with the flowchart of FIG. 2. For convenience, theoperations of FIG. 2 (or any other operations discussed or taughtherein) may be described as being performed by specific components(e.g., components of the system 100). It should be appreciated, however,that these operations may be performed by other types of components andmay be performed using a different number of components. It also shouldbe appreciated that one or more of the operations described herein maynot be employed in a given implementation.

As represented by block 202, at some point in time (e.g., when theaccess point 106 is deployed) a first protocol tunnel is establishedbetween the security gateway 112 and the access point 106. Here, thesecurity gateway 112 and the access point 106 each perform correspondingoperations to establish the protocol tunnel. This may involve, forexample, exchanging messages to allocate cryptographic keys forencrypting and decrypting information sent over the protocol tunnel 142.In addition, as mentioned above, CSAs may be established for thisprotocol tunnel.

As represented by block 204, at some point in time the access terminal102 obtains authentication information. For example, the wirelessoperator for the access terminal 102 may assign authenticationinformation when the access terminal is first provisioned.

As represented by block 206, at some point in time the access terminal102 may identify an access point (e.g., access point 106) on a localnetwork. For example, the access terminal 102 may be associated with ahome femto access point when either of these devices is provisioned.

As represented by block 208, at some point in time the access terminal102 discovers the security gateway associated with the access point 106.For example, the access terminal 102 may be at a location that isoutside the wireless coverage of the access point 106, yet is able toconnect to some other network (e.g., a wireless operator's macronetwork). In this case, the access terminal 102 may attempt to locatethe security gateway that is associated with the access point 106 sothat the access terminal 102 may gain access to its local network. Asdiscussed in more detail in conjunction with FIG. 3, this may involve,for example, the access terminal 102 sending a message to one or moresecurity gateways to find the security gateway that has established atunnel to the access point 106. In conjunction with this message, theaccess terminal 102 sends its authentication information to the securitygateway. The security gateway then takes appropriate action toauthenticate the authentication information (e.g., by communicating withthe authentication server 114). For example, the security gateway maysend the subscription information for the access terminal 102 to theauthentication server 114. The authentication server 114 maintains alist a femto access points that may be accessed as part of thesubscription profile for the access terminal 102 (i.e., the accessterminal subscription profile determines whether a given user isauthorized to use a given femto access point). Based on an identifier(e.g., NAI) received during authentication (e.g., an identifier obtainedas a result of a message sent by the access terminal 102 to the securitygateway 112), the authentication server 114 returns one or more femtoidentifiers to the security gateway, e.g., identifying the femto accesspoints that the access terminal 102 is allowed to access (assuming theaccess terminal 102 is successfully authenticated). The receivedidentifier may also additionally comprise (e.g., imply or have imbeddedwithin) the identity of the femto access point that the access terminalswant to access (e.g., contained as part of the NAI). If multiple femtoidentifiers are returned, the security gateway selects a femtoidentifier (e.g., based on the availability of an IPsec tunnel to thefemto access point and any preference indicated by the access terminal102). In the event the security gateway has established a tunnel to theaccess point 106 (e.g., the access terminal 102 has queried the securitygateway 112) and the authentication information of the access terminal102 has been authenticated, the security gateway sends a response to theaccess terminal and the entities commence setting up the protocol tunnel138.

As represented by block 210, in conjunction with setting up the protocoltunnel 138, an address on the local network is obtained for the accessterminal 102. For example, the security gateway 112 may send a messageto the access point 106 requesting a local address on behalf of theaccess terminal 102. As one example, in a CSA dedicated to remote IPaccess, the security gateway 112 sends a DHCP request or routersolicitation via the tunnel 142 to the access point 106 to request aremote IP address for the access terminal 102. The access point 106 maythen send a request to the router 120 for the local address. Once theaccess point 106 obtains the local address, the access point 106 sendsthe local address to the security gateway 112. The security gateway 112then forwards the local address to the access terminal 102 (e.g., oncethe protocol tunnel 138 is established). For example, the assignedaddress may be sent to the access terminal 102 via an IKE_AUTH message.

As represented by block 212, the security gateway 112 and the accessterminal 102 each perform corresponding operations to establish theprotocol tunnel 138. This may involve, for example, exchanging messagesto allocate cryptographic keys for encrypting and decrypting informationsent over the protocol tunnel 138.

As represented by block 214, once the protocol tunnel 138 isestablished, packets may be routed between the access terminal 102 andthe access point 106 via the protocol tunnels 138 and 142. Here, thesecurity gateway 112 routes packets it receives via one tunnel to theother tunnel. This may be accomplished in various ways. In some cases, aforwarding policy is established at the time of setting up the protocoltunnels. Thus, when a packet is received via a given tunnel, that packetis forwarded based on the policy. Here, the security gateway 112 mayidentify a packet from a given tunnel based on, for example, the IPsecprotocol header encapsulating the packet. In some cases, the securitygateway 112 inspects the packets to obtain an identifier of the source(e.g., the access terminal 102) and/or the destination (e.g., the accesspoint 106) for the packet. The security gateway 112 may then determinethe appropriate tunnel for forwarding the packet based on this extractedidentifier information.

The access point 106 routes packets between the tunnel 142 and the localnetwork. For example, when a packet is received at the access point 106via the tunnel 142, the access point 106 inspects the packet to identifythe destination for the packet on the local network. The access point106 and forwards the packet to the identified destination. FIG. 1illustrates a sample data path 144 for packet flow between the accesspoint 106 and the local node 134 of the local network (e.g., via therouter 120).

As mentioned above, to remotely access a local network associated withan access point, an access terminal may need to discover the securitygateway that is being used by the access point. Here, it may be assumedthat the security gateway is publically reachable (e.g., a node mayreach the security gateway via public IP). FIG. 3 describes twotechniques that may be employed to discover a security gateway. Onetechnique involves domain name server (DNS) resolution and multipleretries. The other technique involves security gateway redirection basedon, for example, subscription information.

As represented by block 302, the access terminal 102 will haveidentified an access point on a local network that the access terminal102 wishes to access. For example, as discussed above in conjunctionwith block 206, the access terminal 102 may acquire a femto identifierof the femto access point on a home network that the access terminal 102is allowed to access.

As represented by block 304, in implementations that employ the DNStechnique, the access terminal 102 sends a DNS query including adesignated domain name of one or more security gateways in the system.In response to this query, the access terminal 102 may receive a list ofone or more security gateway addresses. Using this technique, the accessterminal 102 may attempt to connect to each IP address sequentially.Here, only the correct security gateway will succeed. If the correctsecurity gateway is found, the access terminal may cache the addressinformation for that security gateway as discussed below. In practice,the addresses returned from the DNS server are usually randomized in around robin fashion for load balancing. Hence, it is unlikely that asingle security gateway will be “hit” constantly if this technique isused.

As represented by block 306, the access terminal 102 initiates discoveryfor the security gateway. In a case where the DNS technique is used, theaccess terminal may use an address obtained from the DNS query at thispoint. Regardless of the technique being used, the access terminal 102may send a message to a selected security gateway to determine whetherthat security gateway has established a tunnel to the access point 106.The selected security gateway receives this message from the accessterminal 102 as represented by block 308.

As represented by block 310, the security gateway determines whether atunnel has been established to the access point 106. For example, basedon one or more femto identifiers received from the authentication server114 (e.g., as described above), the security gateway determines whetherthere is already a pre-setup IPsec tunnel to the corresponding femtoaccess point.

As represented by block 312, the security gateway sends an appropriateresponse to the access terminal 102 based on the determination of block310.

If the tunnel has been set up, the tunnel 138 may be established. Here,if the tunnel 142 does not have a CSA associated with remote IP access,the security gateway 112 may request the access point 106 to createanother CSA. The security gateway 112 then connects the new CSA with thetunnel 142 to the access terminal 102. As represented by block 314, theaccess terminal 102 may then maintain the address of the securitygateway 112 (e.g., along with a mapping to the access point 106) so thatthe access terminal 102 may avoid searching for that security gateway inthe future.

If the tunnel had not been set up, the security gateway sends anappropriate response to the access terminal 102. For example, in someimplementations the security gateway may reject the request from anaccess terminal (e.g., via an appropriate error code using IKEv2).

Alternatively, in implementations that employ the redirection technique,the security gateway may redirect the access terminal 102 to the correctsecurity gateway. Here, the operator may maintain a database (e.g.,redirection database 146) that maps access point identifiers (e.g.,femto identifiers) to security gateway addresses. This database is thenmade accessible for the security gateways in the network. Thus, thesecurity gateway may determine the address of the correct securitygateway associated with the designated access point and send thataddress information to the access terminal 102 in the response.

When a femto is being authenticated at the security gateway, theauthentication server 114 may store security addresses for later. Here,different authentication servers (e.g., home AAAs) in the network mayhave some means to retrieve security gateway addresses associated withfemto identifiers from other authentication servers (e.g., femto AAAs)in the network. For example, these different types of authenticationservers may be implemented in the same entity or share the samedatabase.

As represented by block 316, as a result of a rejection or a redirectionresponse, the access terminal 102 commences discovery of anothersecurity gateway. For example, in an implementation that uses theredirection technique, the access terminal 102 may next access thesecurity gateway corresponding to the address provided in the response.In an implementation that uses the DNS technique, the access terminal102 may select the next address in the list of addresses that wasobtained at block 304.

From the above, it should be appreciated that different discoverytechniques may be independently employed or that multiple discoverytechniques may be employed in combination. For example, the DNStechnique and the redirection technique may be employed in combinationsince the access terminal does not need to know whether the securitygateway can redirect or not. In addition, if the security gateway doesnot redirect the access terminal, the access terminal can still try thenext security gateway IP address on its own.

Referring to FIG. 4, sample aspects of the architecture illustrated bythe system 400 will now be described in more detail. The system 400includes components that are similar to the components of FIG. 1.Specifically, the access terminal 402, the access point 406, thesecurity gateway 412, the communication links 418, 422, 426, 428, and430, the router 420, and the Internet 424 are similar to similarly namedcomponents of FIG. 1. FIG. 4 also shows an example where the accesspoint 404 may connect to a PSDN 408 as represented by a communicationlink 416 and the PSDN 408 may connect to an operator network 410 asrepresented by a communication link 418. Other types of networkconnectively may be used in other implementations as well (e.g., asdiscussed in FIG. 1).

As in the system 100 of FIG. 1, the system 400 enables a remotelylocated access terminal 402 to access a local network on which an accesspoint 406 resides. Again, in a typical scenario, the access point 406 isa home femto access point of the access terminal 402 or some otheraccess point that permits access by the access terminal 402.

In this architecture, the access point 406 acts as a virtual privatenetwork gateway for a protocol tunnel established with the accessterminal 402. In FIG. 4, traffic flow between the access terminal 402and the access point 406 is represented by dotted line 436 routed via aprotocol tunnel (e.g., an IPsec tunnel) as represented by a pair oflines 438. Here, the inner source and destination addresses of a packetsent by the access terminal 402 will have local network addresses (e.g.,as assigned by the router 420 through the access point 406 acting as aproxy ARP for the access terminal 402), while the outer source anddestination addresses will be, for example, macro IP address of theaccess terminal 402 and the access point 406, respectively.

Traffic flow between the security gateway 412 and the access point 406is provided via a protocol tunnel (e.g., an IPsec tunnel) as representedby a pair of lines 448. Here, it may be seen that the tunnel 438 iscarried (e.g., encapsulated or layered) within the tunnel 448. Thus,packets arriving at the security gateway 412 from the access point 402are inserted into the tunnel 448. Accordingly, the outer headers for thetunnel 438 including the outer source and destination addressesdescribed in the preceding paragraph are not removed in thisarchitecture. Rather, another set of outer source and destinationaddresses are added to the packet and will be, for example, defined bythe tunnel 448. Thus, when a packet arrives at the access point 406, twolayers of tunnel headers will be removed from the packet to obtain thepacket with the source and destination addresses associated with thelocal network.

Conversely, when sending a packet from the local network to the accessterminal 402, the access point 406 encapsulates the packet fortransmission via tunnel 438, then encapsulates the resulting packet fortransmission via the tunnel 448. The security gateway 412 will thenremove the header for the tunnel 448 and route the packet to the accessterminal 402. With the above in mind, additional details relating to theoperations of the system 400 will be described with reference to theflowchart of FIG. 5.

As represented by block 502, at some point in time a first protocoltunnel is established between the security gateway 412 and the accesspoint 406. The security gateway 412 and the access point 406 eachperform corresponding operations to establish the protocol tunnel. Thismay involve, for example, exchanging messages to allocate cryptographickeys for encrypting and decrypting information sent over the protocoltunnel 448.

As represented by block 504, at some point in time the access terminal402 and the access point exchange authentication information (e.g.,shared authentication information for IKEv2 SA authentication).Advantageously, the authentication information for the tunnel does notneed to be pre-provisioned in the access terminal 402.

For example, the authentication information may be derived locally whilethe access terminal is connected over-the-air through the access point406. Here, if the access terminal is able to access the local networkvia the access point 406 when connected over-the-air to the access point406, the access terminal 402 already has access to any IP hosts on thelocal domain. This capability may thus be preserved when the accessterminal is at a remote location.

Various techniques may be employed here. For example, in a firstalternative, a Diffie-Hellman key exchange may be performed to generatea pre-shared key (PSK) while the access terminal 402 connectsover-the-air locally. In a second alternative, an authenticatedDiffie-Hellman key exchange may be performed to generate a pre-sharedkey (PSK) while the access terminal 402 connects over-the-air locally.In this case, a secret (e.g., password) used for the authentication maybe provided to the user during subscription of the user's service.During the Diffie-Hellman exchange, the user may enter this secret onthe access terminal 402. The access point 406, in turn, may obtain thesecret from the network (e.g., from a AAA entity) during PPPauthentication and authorization. A key also could be generated at thenetwork using AAA exchange (where the access point sends itsDiffie-Hellman values to the network). After the Diffie-Hellmanexchange, the access terminal 402 and the access point share PSK. In athird alternative, EAP-AKA (over PPP) may be used to generate an MSK andthe MSK may then be used as the PSK. In a fourth alternative, GBA may beused to generate PSK between the access terminal 402 and the accesspoint 406. Here, the access point 406 may play the role of NAF andcontact BSF for bootstrapping. At the end of bootstrapping, the accessterminal 402 and the access point 406 share PSK.

The authentication information also may be derived when the accessterminal is connected remotely (e.g., through a macro access point orfemto access point). For example, the authentication information may bederived during IKEv2 SA establishment between the access terminal 402and the access point 406 while the access terminal is in macro coverage(e.g., connected to macro access point 404). A shared key may be derivedusing similar techniques as described in the alternatives above. For thefirst and second alternative, PSK may be generated during IKEv2 INIT_SADiffie-Hellman exchange. For the third alternative, EAP-AKA is performedduring IKEv2. For the fourth alternative, GBA may be used, withstandardized IKEv2 based Ua (NAF—UE) protocol.

The access terminal 402 may acquire the IP address of the access point406 in various ways. In some implementations, when the access point 406is registered with the network, the access point 406 may be assigned afully qualified domain name (FQDN) in a private DNS belonging to theoperator. In this case, the access terminal may use this FQDN to reachthe access point 406. In some implementations, the access terminal 402may learn the IP address of the access point 406 when the accessterminal 402 connected with the access point 406 over-the-air.

Referring again to FIG. 5, as represented by block 506, the accessterminal discovers the access point 406 to be used to access the desiredlocal network. These operations may be similar to the discoveryoperations described above.

As represented by block 508, in conjunction with establishing the secondprotocol tunnel (tunnel 438), an address on the local network isobtained for the access terminal 402. As above, the access point 406 maysend a request to the router 420 for the local address. In some cases,the access point 406 then sends the local address to the securitygateway 412 which, in turn, forwards the local address to the accessterminal 402.

As represented by block 510, the access point 406 and the accessterminal 402 each perform corresponding operations to establish thesecond protocol tunnel. This may involve, for example, exchangingmessages to allocate cryptographic keys for encrypting and decryptinginformation sent over the protocol tunnel 438.

As represented by block 512, once the protocol tunnel 438 isestablished, packets may be routed between the access terminal 402 andthe access point 406 via the protocol tunnels 438 and 448. For atunneled packet received from the access terminal 402, the securitygateway 412 encapsulated the packets for transmission over the tunnel448. For a packet received from the access point 406, the securitygateway 412 removes the encapsulation for the tunnel 448 and sends thetunneled packet to the access point 406. As above, this may beaccomplished using a forwarding policy or some other suitable technique.

Also as above, the access point 406 routes packets between the tunnels448 and 438 and the local network. For example, when packets arereceived at the access point 406 via the tunnels, the access point 406inspects the packets to identify the destination for the packet on thelocal network. The access point 406 and forwards the packet to theidentified destination. FIG. 4 illustrates a sample data path 444 forpacket flow between the access point 406 and the local node 434 of thelocal network (e.g., via the router 420).

FIG. 6 illustrates several sample components that may be incorporatedinto nodes such as an access terminal 602, an access point 604, asecurity gateway 606, and an authentication server 642 (e.g.,corresponding to the access terminal 102 or 402, the access point 106 or406, the security gateway 112 or 412, and the authentication server 114,respectively) to perform access operations as taught herein. Thedescribed components also may be incorporated into other nodes in acommunication system. For example, other nodes in a system may includecomponents similar to those described for the access terminal 602, theaccess point 604, and the security gateway 606 to provide similarfunctionality. A given node may contain one or more of the describedcomponents. For example, an access terminal may contain multipletransceiver components that enable the access terminal to operate onmultiple frequencies and/or communicate via different technologies.

As shown in FIG. 6, the access terminal 602 and the access point 604 mayinclude transceivers 608 and 610, respectively, for communicating withother nodes. The transceiver 608 includes a transmitter 612 for sendingsignals (e.g., to an access point) and a receiver 614 for receivingsignals (e.g., from an access point). Similarly, the transceiver 610includes a transmitter 616 for sending signals and a receiver 618 forreceiving signals.

The access point 604 and the network node 606 also include networkinterfaces 620 and 622, respectively, for communicating with one anotheror other network nodes. For example, the network interfaces 620 and 622may be configured to communicate with one or more network nodes via awired or wireless backhaul.

The access terminal 602, the access point 604, and the security gateway606 also include other components that may be used in conjunction withaccess operations as taught herein. For example, the access terminal602, the access point 604, the security gateway 606, and theauthentication server 114 include communication controllers 624, 626,628, and 644, respectively, for managing communication with other nodes(e.g., processing and inspecting packets, obtaining authenticationinformation, obtaining identifiers, or sending and receiving packets,messages, requests, addresses, authentication information, responses, orqueries) and for providing other related functionality as taught herein.In addition, the access terminal 602, the access point 604, and thesecurity gateway 606 include tunnel controllers 620, 632, and 634,respectively, for establishing tunnels and for providing other relatedfunctionality (e.g., accepting or rejecting access terminal access to atunnel) as taught herein. The access terminal 602 includes a mobilitycontroller 636 for identifying access points to be accessed and forproviding other related functionality as taught herein. The accessterminal 602 includes a data memory 638 for maintain security gatewayaddresses and for providing other related functionality as taughtherein. The access point 604 includes an address controller 640 forobtaining local addresses and for providing other related functionalityas taught herein. The authentication server 642 includes a database 646for storing subscription information for providing other relatedfunctionality as taught herein.

For convenience the access terminal 602 and the access point 604 areshown in FIG. 6 as including components that may be used in the variousexamples described herein. In practice, one or more of the illustratedcomponents may be implemented in a different way in a different example.As an example, the tunnel controllers 630, 632, and 634 may havedifferent functionality and/or operate in a different manner (e.g.,establish tunnels in a different manner) in the implementation of FIG. 1as compared to the implementation of FIG. 4.

Also, in some implementations the components of FIG. 6 may beimplemented in one or more processors (e.g., that uses and/orincorporates data memory). For example, the functionality of blocks 624,630, 636, and 638 may be implemented by a processor or processors of anaccess terminal, the functionality of blocks 620, 626, 632, and 640 maybe implemented by a processor or processors in of access point, and thefunctionality of blocks 622, 628, and 624 may be implemented by aprocessor or processors in a network node.

As discussed above, in some aspects the teachings herein may be employedin a network that includes macro scale coverage (e.g., a large areacellular network such as a 3G network, typically referred to as a macrocell network or a wide area network) and smaller scale coverage (e.g., aresidence-based or building-based network environment). As an accessterminal moves through such a network, the access terminal may be servedin certain locations by access points that provide macro coverage whilethe access terminal may be served at other locations by access pointsthat provide smaller scale coverage. In some aspects, the smallercoverage access points may be used to provide incremental capacitygrowth, in-building coverage, and different services (e.g., for a morerobust user experience).

In the description herein, a node that provides coverage over arelatively large area may be referred to as a macro access point while anode that provides coverage over a relatively small area (e.g., aresidence) may be referred to as a femto access point. It should beappreciated that the teachings herein may be applicable to nodesassociated with other types of coverage areas. For example, a picoaccess point may provide coverage (e.g., coverage within a commercialbuilding) over an area that is smaller than a macro area and larger thana femto area. In various applications, other terminology may be used toreference a macro access point, a femto access point, or other accesspoint-type nodes. For example, a macro access point may be configured orreferred to as an access node, base station, access point, eNodeB, macrocell, and so on. Also, a femto access point may be configured orreferred to as a Home NodeB, Home eNodeB, access point base station,femto cell, and so on. In some implementations, a node may be associatedwith (e.g., divided into) one or more cells or sectors. A cell or sectorassociated with a macro access point, a femto access point, or a picoaccess point may be referred to as a macro cell, a femto cell, or a picocell, respectively.

FIG. 7 illustrates a wireless communication system 700, configured tosupport a number of users, in which the teachings herein may beimplemented. The system 700 provides communication for multiple cells702, such as, for example, macro cells 702A-702G, with each cell beingserviced by a corresponding access point 704 (e.g., access points704A-704G). As shown in FIG. 7, access terminals 706 (e.g., accessterminals 706A-706L) may be dispersed at various locations throughoutthe system over time. Each access terminal 706 may communicate with oneor more access points 704 on a forward link (FL) and/or a reverse link(RL) at a given moment, depending upon whether the access terminal 706is active and whether it is in soft handoff, for example. The wirelesscommunication system 700 may provide service over a large geographicregion. For example, macro cells 702A-702G may cover a few blocks in aneighborhood or several miles in rural environment.

FIG. 8 illustrates an exemplary communication system 800 where one ormore femto access points are deployed within a network environment.Specifically, the system 800 includes multiple femto access points 810(e.g., femto access points 810A and 810B) installed in a relativelysmall scale network environment (e.g., in one or more user residences830). Each femto access point 810 may be coupled to a wide area network840 (e.g., the Internet) and a mobile operator core network 850 via aDSL router, a cable modem, a wireless link, or other connectivity means(not shown). As will be discussed below, each femto access point 810 maybe configured to serve associated access terminals 820 (e.g., accessterminal 820A) and, optionally, other (e.g., hybrid or alien) accessterminals 820 (e.g., access terminal 820B). In other words, access tofemto access points 810 may be restricted whereby a given accessterminal 820 may be served by a set of designated (e.g., home) femtoaccess point(s) 810 but may not be served by any non-designated femtoaccess points 810 (e.g., a neighbor's femto access point 810).

FIG. 9 illustrates an example of a coverage map 900 where severaltracking areas 902 (or routing areas or location areas) are defined,each of which includes several macro coverage areas 904. Here, areas ofcoverage associated with tracking areas 902A, 902B, and 902C aredelineated by the wide lines and the macro coverage areas 904 arerepresented by the larger hexagons. The tracking areas 902 also includefemto coverage areas 906. In this example, each of the femto coverageareas 906 (e.g., femto coverage area 906C) is depicted within one ormore macro coverage areas 904 (e.g., macro coverage area 904B). Itshould be appreciated, however, that some or all of a femto coveragearea 906 may not lie within a macro coverage area 904. In practice, alarge number of femto coverage areas 906 may be defined with a giventracking area 902 or macro coverage area 904. Also, one or more picocoverage areas (not shown) may be defined within a given tracking area902 or macro coverage area 904.

Referring again to FIG. 8, the owner of a femto access point 810 maysubscribe to mobile service, such as, for example, 3G mobile service,offered through the mobile operator core network 850. In addition, anaccess terminal 820 may be capable of operating both in macroenvironments and in smaller scale (e.g., residential) networkenvironments. In other words, depending on the current location of theaccess terminal 820, the access terminal 820 may be served by a macrocell access point 860 associated with the mobile operator core network850 or by any one of a set of femto access points 810 (e.g., the femtoaccess points 810A and 810B that reside within a corresponding userresidence 830). For example, when a subscriber is outside his home, heis served by a standard macro access point (e.g., access point 860) andwhen the subscriber is at home, he is served by a femto access point(e.g., access point 810A). Here, a femto access point 810 may bebackward compatible with legacy access terminals 820.

A femto access point 810 may be deployed on a single frequency or, inthe alternative, on multiple frequencies. Depending on the particularconfiguration, the single frequency or one or more of the multiplefrequencies may overlap with one or more frequencies used by a macroaccess point (e.g., access point 860).

In some aspects, an access terminal 820 may be configured to connect toa preferred femto access point (e.g., the home femto access point of theaccess terminal 820) whenever such connectivity is possible. Forexample, whenever the access terminal 820A is within the user'sresidence 830, it may be desired that the access terminal 820Acommunicate only with the home femto access point 810A or 810B.

In some aspects, if the access terminal 820 operates within the macrocellular network 850 but is not residing on its most preferred network(e.g., as defined in a preferred roaming list), the access terminal 820may continue to search for the most preferred network (e.g., thepreferred femto access point 810) using a better system reselection(BSR) procedure, which may involve a periodic scanning of availablesystems to determine whether better systems are currently available andsubsequently acquire such preferred systems. The access terminal 820 maylimit the search for specific band and channel. For example, one or morefemto channels may be defined whereby all femto access points (or allrestricted femto access points) in a region operate on the femtochannel(s). The search for the most preferred system may be repeatedperiodically. Upon discovery of a preferred femto access point 810, theaccess terminal 820 selects the femto access point 810 and registers onit for use when within its coverage area.

Access to a femto access point may be restricted in some aspects. Forexample, a given femto access point may only provide certain services tocertain access terminals. In deployments with so-called restricted (orclosed) access, a given access terminal may only be served by the macrocell mobile network and a defined set of femto access points (e.g., thefemto access points 810 that reside within the corresponding userresidence 830). In some implementations, an access point may berestricted to not provide, for at least one access point, at least oneof: signaling, data access, registration, paging, or service.

In some aspects, a restricted femto access point (which may also bereferred to as a Closed Subscriber Group Home NodeB) is one thatprovides service to a restricted provisioned set of access terminals.This set may be temporarily or permanently extended as necessary. Insome aspects, a Closed Subscriber Group (CSG) may be defined as the setof access points (e.g., femto access points) that share a common accesscontrol list of access terminals.

Various relationships may thus exist between a given femto access pointand a given access terminal. For example, from the perspective of anaccess terminal, an open femto access point may refer to a femto accesspoint with unrestricted access (e.g., the femto access point allowsaccess to any access terminal). A restricted femto access point mayrefer to a femto access point that is restricted in some manner (e.g.,restricted for access and/or registration). A home femto access pointmay refer to a femto access point on which the access terminal isauthorized to access and operate on (e.g., permanent access is providedfor a defined set of one or more access terminals). A guest (or hybrid)femto access point may refer to a femto access point on which an accessterminal is temporarily authorized to access or operate on. An alienfemto access point may refer to a femto access point on which the accessterminal is not authorized to access or operate on, except for perhapsemergency situations (e.g., 911 calls).

From a restricted femto access point perspective, a home access terminalmay refer to an access terminal that is authorized to access therestricted femto access point installed in the residence of that accessterminal's owner (usually the home access terminal has permanent accessto that femto access point). A guest access terminal may refer to anaccess terminal with temporary access to the restricted femto accesspoint (e.g., limited based on deadline, time of use, bytes, connectioncount, or some other criterion or criteria). An alien access terminalmay refer to an access terminal that does not have permission to accessthe restricted femto access point, except for perhaps emergencysituations, for example, such as 911 calls (e.g., an access terminalthat does not have the authentication information or permission toregister with the restricted femto access point).

For convenience, the disclosure herein describes various functionalityin the context of a femto access point. It should be appreciated,however, that a pico access point may provide the same or similarfunctionality for a larger coverage area. For example, a pico accesspoint may be restricted, a home pico access point may be defined for agiven access terminal, and so on.

The teachings herein may be employed in a wireless multiple-accesscommunication system that simultaneously supports communication formultiple wireless access terminals. Here, each terminal may communicatewith one or more access points via transmissions on the forward andreverse links. The forward link (or downlink) refers to thecommunication link from the access points to the terminals, and thereverse link (or uplink) refers to the communication link from theterminals to the access points. This communication link may beestablished via a single-in-single-out system, amultiple-in-multiple-out (MIMO) system, or some other type of system.

A MIMO system employs multiple (N_(T)) transmit antennas and multiple(N_(R)) receive antennas for data transmission. A MIMO channel formed bythe N_(T) transmit and N_(R) receive antennas may be decomposed intoN_(S) independent channels, which are also referred to as spatialchannels, where N_(S)≦min{N_(T),N_(R)}. Each of the Ns independentchannels corresponds to a dimension. The MIMO system may provideimproved performance (e.g., higher throughput and/or greaterreliability) if the additional dimensionalities created by the multipletransmit and receive antennas are utilized.

A MIMO system may support time division duplex (TDD) and frequencydivision duplex (FDD). In a TDD system, the forward and reverse linktransmissions are on the same frequency region so that the reciprocityprinciple allows the estimation of the forward link channel from thereverse link channel. This enables the access point to extract transmitbeam-forming gain on the forward link when multiple antennas areavailable at the access point.

FIG. 10 illustrates a wireless device 1010 (e.g., an access point) and awireless device 1050 (e.g., an access terminal) of a sample MIMO system1000. At the device 1010, traffic data for a number of data streams isprovided from a data source 1012 to a transmit (TX) data processor 1014.Each data stream may then be transmitted over a respective transmitantenna.

The TX data processor 1014 formats, codes, and interleaves the trafficdata for each data stream based on a particular coding scheme selectedfor that data stream to provide coded data. The coded data for each datastream may be multiplexed with pilot data using OFDM techniques. Thepilot data is typically a known data pattern that is processed in aknown manner and may be used at the receiver system to estimate thechannel response. The multiplexed pilot and coded data for each datastream is then modulated (i.e., symbol mapped) based on a particularmodulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for thatdata stream to provide modulation symbols. The data rate, coding, andmodulation for each data stream may be determined by instructionsperformed by a processor 1030. A data memory 1032 may store programcode, data, and other information used by the processor 1030 or othercomponents of the device 1010.

The modulation symbols for all data streams are then provided to a TXMIMO processor 1020, which may further process the modulation symbols(e.g., for OFDM). The TX MIMO processor 1020 then provides NT modulationsymbol streams to N_(T) transceivers (XCVR) 1022A through 1022T. In someaspects, the TX MIMO processor 1020 applies beam-forming weights to thesymbols of the data streams and to the antenna from which the symbol isbeing transmitted.

Each transceiver 1022 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. N_(T)modulated signals from transceivers 1022A through 1022T are thentransmitted from N_(T) antennas 1024A through 1024T, respectively.

At the device 1050, the transmitted modulated signals are received byN_(R) antennas 1052A through 1052R and the received signal from eachantenna 1052 is provided to a respective transceiver (XCVR) 1054Athrough 1054R. Each transceiver 1054 conditions (e.g., filters,amplifies, and downconverts) a respective received signal, digitizes theconditioned signal to provide samples, and further processes the samplesto provide a corresponding “received” symbol stream.

A receive (RX) data processor 1060 then receives and processes the NRreceived symbol streams from N_(R) transceivers 1054 based on aparticular receiver processing technique to provide N_(T) “detected”symbol streams. The RX data processor 1060 then demodulates,deinterleaves, and decodes each detected symbol stream to recover thetraffic data for the data stream. The processing by the RX dataprocessor 1060 is complementary to that performed by the TX MIMOprocessor 1020 and the TX data processor 1014 at the device 1010.

A processor 1070 periodically determines which pre-coding matrix to use(discussed below). The processor 1070 formulates a reverse link messagecomprising a matrix index portion and a rank value portion. A datamemory 1072 may store program code, data, and other information used bythe processor 1070 or other components of the device 1050.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 1038,which also receives traffic data for a number of data streams from adata source 1036, modulated by a modulator 1080, conditioned by thetransceivers 1054A through 1054R, and transmitted back to the device1010.

At the device 1010, the modulated signals from the device 1050 arereceived by the antennas 1024, conditioned by the transceivers 1022,demodulated by a demodulator (DEMOD) 1040, and processed by a RX dataprocessor 1042 to extract the reverse link message transmitted by thedevice 1050. The processor 1030 then determines which pre-coding matrixto use for determining the beam-forming weights then processes theextracted message.

FIG. 10 also illustrates that the communication components may includeone or more components that perform access control operations as taughtherein. For example, an access control component 1090 may cooperate withthe processor 1030 and/or other components of the device 1010 tosend/receive signals to/from another device (e.g., device 1050) astaught herein. Similarly, an access control component 1092 may cooperatewith the processor 1070 and/or other components of the device 1050 tosend/receive signals to/from another device (e.g., device 1010). Itshould be appreciated that for each device 1010 and 1050 thefunctionality of two or more of the described components may be providedby a single component. For example, a single processing component mayprovide the functionality of the access control component 1090 and theprocessor 1030 and a single processing component may provide thefunctionality of the access control component 1092 and the processor1070. In some implementations, the processor 1030 and the memory 1032may collectively provide access-related and other functionality astaught herein for the device 1010, and the processor 1070 and the memory1072 may collectively provide access-related and other functionality astaught herein for the device 1050.

The teachings herein may be incorporated into various types ofcommunication systems and/or system components. In some aspects, theteachings herein may be employed in a multiple-access system capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., by specifying one or more of bandwidth, transmitpower, coding, interleaving, and so on). For example, the teachingsherein may be applied to any one or combinations of the followingtechnologies: Code Division Multiple Access (CDMA) systems,Multiple-Carrier CDMA (MCCDMA), Wideband CDMA (W-CDMA), High-SpeedPacket Access (HSPA, HSPA+) systems, Time Division Multiple Access(TDMA) systems, Frequency Division Multiple Access (FDMA) systems,Single-Carrier FDMA (SC-FDMA) systems, Orthogonal Frequency DivisionMultiple Access (OFDMA) systems, or other multiple access techniques. Awireless communication system employing the teachings herein may bedesigned to implement one or more standards, such as IS-95, cdma2000,IS-856, W-CDMA, TDSCDMA, and other standards. A CDMA network mayimplement a radio technology such as Universal Terrestrial Radio Access(UTRA), cdma2000, or some other technology. UTRA includes W-CDMA and LowChip Rate (LCR). The cdma2000 technology covers IS-2000, IS-95 andIS-856 standards. A TDMA network may implement a radio technology suchas Global System for Mobile Communications (GSM). An OFDMA network mayimplement a radio technology such as Evolved UTRA (E-UTRA), IEEE 802.11,IEEE 802.16, IEEE 802.20, Flash-OFDM®, etc. UTRA, E-UTRA, and GSM arepart of Universal Mobile Telecommunication System (UMTS). The teachingsherein may be implemented in a 3GPP Long Term Evolution (LTE) system, anUltra-Mobile Broadband (UMB) system, and other types of systems. LTE isa release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE aredescribed in documents from an organization named “3rd GenerationPartnership Project” (3GPP), while cdma2000 is described in documentsfrom an organization named “3rd Generation Partnership Project 2”(3GPP2). Although certain aspects of the disclosure may be describedusing 3GPP terminology, it is to be understood that the teachings hereinmay be applied to 3GPP (e.g., Re199, Re15, Re16, Re17) technology, aswell as 3GPP2 (e.g., 1×RTT, 1×EV-DO RelO, RevA, RevB) technology andother technologies.

The teachings herein may be incorporated into (e.g., implemented withinor performed by) a variety of apparatuses (e.g., nodes). In someaspects, a node (e.g., a wireless node) implemented in accordance withthe teachings herein may comprise an access point or an access terminal.

For example, an access terminal may comprise, be implemented as, orknown as user equipment, a subscriber station, a subscriber unit, amobile station, a mobile, a mobile node, a remote station, a remoteterminal, a user terminal, a user agent, a user device, or some otherterminology. In some implementations an access terminal may comprise acellular telephone, a cordless telephone, a session initiation protocol(SIP) phone, a wireless local loop (WLL) station, a personal digitalassistant (PDA), a handheld device having wireless connectioncapability, or some other suitable processing device connected to awireless modem. Accordingly, one or more aspects taught herein may beincorporated into a phone (e.g., a cellular phone or smart phone), acomputer (e.g., a laptop), a portable communication device, a portablecomputing device (e.g., a personal data assistant), an entertainmentdevice (e.g., a music device, a video device, or a satellite radio), aglobal positioning system device, or any other suitable device that isconfigured to communicate via a wireless medium.

An access point may comprise, be implemented as, or known as a NodeB, aneNodeB, a radio network controller (RNC), a base station (BS), a radiobase station (RBS), a base station controller (BSC), a base transceiverstation (BTS), a transceiver function (TF), a radio transceiver, a radiorouter, a basic service set (BSS), an extended service set (ESS), amacro cell, a macro node, a Home eNB (HeNB), a femto cell, a femto node,a pico node, or some other similar terminology.

In some aspects a node (e.g., an access point) may comprise an accessnode for a communication system. Such an access node may provide, forexample, connectivity for or to a network (e.g., a wide area networksuch as the Internet or a cellular network) via a wired or wirelesscommunication link to the network. Accordingly, an access node mayenable another node (e.g., an access terminal) to access a network orsome other functionality. In addition, it should be appreciated that oneor both of the nodes may be portable or, in some cases, relativelynon-portable.

Also, it should be appreciated that a wireless node may be capable oftransmitting and/or receiving information in a non-wireless manner(e.g., via a wired connection). Thus, a receiver and a transmitter asdiscussed herein may include appropriate communication interfacecomponents (e.g., electrical or optical interface components) tocommunicate via a non-wireless medium.

A wireless node may communicate via one or more wireless communicationlinks that are based on or otherwise support any suitable wirelesscommunication technology. For example, in some aspects a wireless nodemay associate with a network. In some aspects the network may comprise alocal area network or a wide area network. A wireless device may supportor otherwise use one or more of a variety of wireless communicationtechnologies, protocols, or standards such as those discussed herein(e.g., CDMA, TDMA, OFDM, OFDMA, WiMAX, Wi-Fi, and so on). Similarly, awireless node may support or otherwise use one or more of a variety ofcorresponding modulation or multiplexing schemes. A wireless node maythus include appropriate components (e.g., air interfaces) to establishand communicate via one or more wireless communication links using theabove or other wireless communication technologies. For example, awireless node may comprise a wireless transceiver with associatedtransmitter and receiver components that may include various components(e.g., signal generators and signal processors) that facilitatecommunication over a wireless medium.

The functionality described herein (e.g., with regard to one or more ofthe accompanying figures) may correspond in some aspects to similarlydesignated “means for” functionality in the appended claims. Referringto FIGS. 11-14, apparatuses 1100, 1200, 1300, and 1400 are representedas a series of interrelated functional modules. Here, a first tunnelestablishing module 1102, a second tunnel establishing module 1104, achild security associations establishing module 1118, a tunnel accessrequest receiving module 1120, an established tunnel determining module1122, and an access terminal redirecting module 1124 may correspond atleast in some aspects to, for example, a tunnel controller as discussedherein. A packet determining module 1106, a received packet forwardingmodule 1108, an address request sending module 1110, an addressreceiving module 1112, an address sending module 1114, an authenticationinformation receiving module 1116 may correspond at least in someaspects to, for example, a communication controller as discussed herein.An access point identifying module 1202 may correspond at least in someaspects to, for example, a mobility controller as discussed herein. Asecurity gateway message sending module 1204, a message responsereceiving module 1206, a DNS query sending module 1208, and a securitygateway address receiving module 1210 may correspond at least in someaspects to, for example, a communication controller as discussed herein.A security gateway address maintaining module 1212 may correspond atleast in some aspects to, for example, a data memory as discussedherein. A tunnel establishing module 1214 may correspond at least insome aspects to, for example, a tunnel controller as discussed herein. Asecurity gateway tunnel establishing module 1302, a child securityassociations establishing module 1316, and an access terminal tunnelestablishing module 1318 may correspond at least in some aspects to, forexample, a tunnel controller as discussed herein. A local networkaddress obtaining module 1304 may correspond at least in some aspectsto, for example, an address controller as discussed herein. An addressmessage sending module 1306, a packet transferring module 1308, anaddress request receiving module 1310, a packet inspecting module 1312,and a packet forwarding module 1314 may correspond at least in someaspects to, for example, a communication controller as discussed herein.A first tunnel establishing module 1402 and a second tunnel establishingmodule 1406 may correspond at least in some aspects to, for example, atunnel controller as discussed herein. An authentication informationobtaining module 1404, a packet receiving module 1412, a packetinspecting module 1414 and a packet forwarding module 1416 maycorrespond at least in some aspects to, for example, a communicationcontroller as discussed herein. A local network address obtaining module1408 and an address sending module 1410 may correspond at least in someaspects to, for example, an address controller as discussed herein. Anaccess point identifying module 1502 may correspond at least in someaspects to, for example, a mobility controller as discussed herein. Amessage sending module 1504 may correspond at least in some aspects to,for example, a communication controller as discussed herein. An accesspoint identifying module 1602 may correspond at least in some aspectsto, for example, a communication controller as discussed herein. Anidentifier storing module 1604 may correspond at least in some aspectsto, for example, a database as discussed herein. A subscriptioninformation using module 1606 may correspond at least in some aspectsto, for example, a database as discussed herein.

The functionality of the modules of FIGS. 11-14 may be implemented invarious ways consistent with the teachings herein. In some aspects thefunctionality of these modules may be implemented as one or moreelectrical components. In some aspects the functionality of these blocksmay be implemented as a processing system including one or moreprocessor components. In some aspects the functionality of these modulesmay be implemented using, for example, at least a portion of one or moreintegrated circuits (e.g., an ASIC). As discussed herein, an integratedcircuit may include a processor, software, other related components, orsome combination thereof. The functionality of these modules also may beimplemented in some other manner as taught herein. In some aspects oneor more of any dashed blocks in FIGS. 11-14 are optional.

It should be understood that any reference to an element herein using adesignation such as “first,” “second,” and so forth does not generallylimit the quantity or order of those elements. Rather, thesedesignations may be used herein as a convenient method of distinguishingbetween two or more elements or instances of an element. Thus, areference to first and second elements does not mean that only twoelements may be employed there or that the first element must precedethe second element in some manner. Also, unless stated otherwise a setof elements may comprise one or more elements. In addition, terminologyof the form “at least one of: A, B, or C” used in the description or theclaims means “A or B or C or any combination of these elements.”

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that any of the variousillustrative logical blocks, modules, processors, means, circuits, andalgorithm steps described in connection with the aspects disclosedherein may be implemented as electronic hardware (e.g., a digitalimplementation, an analog implementation, or a combination of the two,which may be designed using source coding or some other technique),various forms of program or design code incorporating instructions(which may be referred to herein, for convenience, as “software” or a“software module”), or combinations of both. To clearly illustrate thisinterchangeability of hardware and software, various illustrativecomponents, blocks, modules, circuits, and steps have been describedabove generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implementedwithin or performed by an integrated circuit (IC), an access terminal,or an access point. The IC may comprise a general purpose processor, adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, electrical components, optical components,mechanical components, or any combination thereof designed to performthe functions described herein, and may execute codes or instructionsthat reside within the IC, outside of the IC, or both. A general purposeprocessor may be a microprocessor, but in the alternative, the processormay be any conventional processor, controller, microcontroller, or statemachine. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor, aplurality of microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

It is understood that any specific order or hierarchy of steps in anydisclosed process is an example of a sample approach. Based upon designpreferences, it is understood that the specific order or hierarchy ofsteps in the processes may be rearranged while remaining within thescope of the present disclosure. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

In one or more exemplary embodiments, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media. It should beappreciated that a computer-readable medium may be implemented in anysuitable computer-program product.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present disclosure.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects without departing from the scope of thedisclosure. Thus, the present disclosure is not intended to be limitedto the aspects shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A method of communication, comprising: identifying an access point on a local network to be accessed by an access terminal; sending a message from the access terminal to a security gateway to determine whether the security gateway has established a protocol tunnel to the access point; and receiving a response to the message from the security gateway, wherein the response indicates whether the security gateway has established a protocol tunnel to the access point.
 2. The method of claim 1, wherein, if the response indicates that the security gateway has not established a protocol tunnel to the access point, the method further comprises sending another message from the access terminal to another security gateway to determine whether the another security gateway has established a protocol tunnel to the access point.
 3. The method of claim 2, further comprising: sending a domain name system query to determine at least one security gateway address; and receiving a plurality of security gateway addresses in response to the query, wherein the security gateway addresses are used to send the message to the security gateway and to send the another message to the another gateway.
 4. The method of claim 1, wherein the response comprises a redirection to another security gateway.
 5. The method of claim 1, further comprising maintaining an address of the security gateway for future remote accesses of the local network if the response indicates that the security gateway has established a protocol tunnel to the access point.
 6. The method of claim 1, further comprising establishing another protocol tunnel between the access terminal and the security gateway to enable the access terminal to remotely access the local network if the response indicates that the security gateway has established a protocol tunnel to the access point.
 7. The method of claim 6, wherein the protocol tunnel and the another protocol tunnel comprise IPsec tunnels.
 8. The method of claim 1, wherein the access point comprises a femto access point.
 9. An apparatus for communication, comprising: a mobility controller configure to identify an access point on a local network to be accessed by an access terminal; and a communication controller configured to send a message from the access terminal to a security gateway to determine whether the security gateway has established a protocol tunnel to the access point, and further configured to receive a response to the message from the security gateway, wherein the response indicates whether the security gateway has established a protocol tunnel to the access point.
 10. The apparatus of claim 9, wherein the communication controller is further configured to: send a domain name system query to determine at least one security gateway address; and receive a plurality of security gateway addresses in response to the query, wherein the security gateway addresses are used to send the message to the security gateway.
 11. The apparatus of claim 9, wherein the response comprises a redirection to another security gateway.
 12. The apparatus of claim 9, further comprising a tunnel controller configured to establish another protocol tunnel between the access terminal and the security gateway to enable the access terminal to remotely access the local network if the response indicates that the security gateway has established a protocol tunnel to the access point.
 13. An apparatus for communication, comprising: means for identifying an access point on a local network to be accessed by an access terminal; means for sending a message from the access terminal to a security gateway to determine whether the security gateway has established a protocol tunnel to the access point; and means for receiving a response to the message from the security gateway, wherein the response indicates whether the security gateway has established a protocol tunnel to the access point.
 14. The apparatus of claim 13, further comprising: means for sending a domain name system query to determine at least one security gateway address; and means for receiving a plurality of security gateway addresses in response to the query, wherein the security gateway addresses are used to send the message to the security gateway.
 15. The apparatus of claim 13, wherein the response comprises a redirection to another security gateway.
 16. The apparatus of claim 13, further comprising means for establishing another protocol tunnel between the access terminal and the security gateway to enable the access terminal to remotely access the local network if the response indicates that the security gateway has established a protocol tunnel to the access point.
 17. A non-transitory computer-readable medium storing computer executable code for causing the computer to: identify an access point on a local network to be accessed by an access terminal; send a message from the access terminal to a security gateway to determine whether the security gateway has established a protocol tunnel to the access point; and receive a response to the message from the security gateway, wherein the response indicates whether the security gateway has established a protocol tunnel to the access point.
 18. The computer-readable medium of claim 17, wherein the computer-readable medium further comprises code for causing the computer to: send a domain name system query to determine at least one security gateway address; and receive a plurality of security gateway addresses in response to the query, wherein the security gateway addresses are used to send the message to the security gateway.
 19. The computer-readable medium of claim 17, wherein the response comprises a redirection to another security gateway.
 20. The computer-readable medium of claim 17, wherein the computer-readable medium further comprises code for causing the computer to establish another protocol tunnel between the access terminal and the security gateway to enable the access terminal to remotely access the local network if the response indicates that the security gateway has established a protocol tunnel to the access point.
 21. A method of communication, comprising: identifying a femto access point to be accessed by an access terminal; and sending a message from the access terminal to a security gateway to enable the access terminal to access the femto access point, wherein the message comprises an identifier of the femto access point.
 22. The method of claim 21, wherein the femto identifier is embedded in another identifier that the access terminal uses for authentication with the security gateway.
 23. An apparatus for communication, comprising: a mobility controller configured to identify a femto access point to be accessed by an access terminal; and a communication controller configured to send a message from the access terminal to a security gateway to enable the access terminal to access the femto access point, wherein the message comprises an identifier of the femto access point.
 24. The apparatus of claim 23, wherein the femto identifier is embedded in another identifier that the access terminal uses for authentication with the security gateway.
 25. An apparatus for communication, comprising: means for identifying a femto access point to be accessed by an access terminal; and means for sending a message from the access terminal to a security gateway to enable the access terminal to access the femto access point, wherein the message comprises an identifier of the femto access point.
 26. The apparatus of claim 25, wherein the femto identifier is embedded in another identifier that the access terminal uses for authentication with the security gateway.
 27. A non-transitory computer-readable medium storing computer executable code for causing the computer to: identify a femto access point to be accessed by an access terminal; and send a message from the access terminal to a security gateway to enable the access terminal to access the femto access point, wherein the message comprises an identifier of the femto access point.
 28. The computer-readable medium of claim 27, wherein the femto identifier is embedded in another identifier that the access terminal uses for authentication with the security gateway. 